Apparatus for winding tapes and films

ABSTRACT

An apparatus for winding tapes and films where the support for the roll is lineally or pivotally displaced in response to the change in roll diameter which is sensed by electrical control means, and where a contact roller is applied against the roll with an adjustable predetermined pressure. The bearing for the contact roller is arranged to yield in response to the tape tension, the measurement of its displacement giving a continuous reading of the latter.

llnited States Patent 1191 liampi 11] 3,834,642 [451 Sept. 10,1974

[ APPARATUS FOR WINDING TAPES AND FlLMS [75] Inventor: Eberhard Kampi, Munich, Germany [73] Assignee: Erwin Kampf Maschinenfabrik,

Munich, Germany 22 Filed: Mar. 6, 1973 [21] Appl.No.:338,638

[30] Foreign Application Priority Data Mar. 24, 1972 Germany 2214350 [52] 11.8. C1. 242/755, 242/67.1 R [51] 1nt.'Cl B65h 23/00, B65h 17/02 [58] Field of Search 242/755, 75.51, 62.1 R, 242/672 [56] References Cited UNITED STATES PATENTS 3,042,333 7/1962 Wilder 242/75.5

3,387,798 6/1968 Young 242/67. 1 R 3,670,980 6/1972 Mukai 242/67.l R FOREIGN PATENTS OR APPLICATIONS 1,196,042 7/1965 Germany 242/67.l R 800,462 12/1968 Canada 242/67.l R

Primary Examiner-John W. Huckert Assistant Examiner-Edward J. McCarthy Attorney, Agent, or Firm-Bacon & Thomas 5 7] ABSTRACT An apparatus for winding tapes and films where the support for the roll is lineally or pivotally displaced in response to the change in roll diameter which is sensed by electrical control means, and where a contact roller is applied against the roll with an adjustable predetermined pressure. The bearing for the contact roller is arranged to yield in response to the tape tension, the measurement of its displacement giving a continuous reading of the latter.

12 Claims, 2 Drawing Figures PATENIEB SEP 1 01074 F EET 1 0F 2 PATENTEB SEP 1 01974 SHEEI 2 OF 2 I APPARATUS FOR WINDING TAPES AND FILMS BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to roll winding devices, and in particular to devices for the winding of tapes and films which include a contact roller and means for adjusting the distance between the contact roller and the winding roll support.

2. Description of the Prior Art The winding of thin tapes and films requires a carefully adjusted winding device, in order to obtain a roll of the desired stability, without'causing any damage to the tape or film itself. For this type of operation, it is known to use a contact rollerand to adjust the contact pressure exerted by that contact roller against the winding roll in relation to the type of material being wound-and to the necessary stability of the roll. An additional requirement relates to the maintenance of the tape tension during winding within low limits of stress so as to prevent stretching or rupture on the one hand, while permitting operation of the winding'device at high speeds on the other hand.

Known prior art devices of this type include a means for applying through the contact roller support a predetermined contact pressure against the winding roll. The contact roller support is shifted in response to the increase in roll diameter and operates an electric switch at the end of a given displacement distance. This switch initiates a step-by-step retracting displacement of the winding roll support. The tape tension is simultaneously adjusted in response to the roll diameter which is indicated by the displacement distance of the winding roll support. However, because of the step-by-step retracting motion of the winding roll support, no continuous measurement of the roll diameter is available and no continuous adjustment of the tape tension is therefore possible. There exists a mutual interaction between the contact pressure and the tape tension. It is thus necessary that the contact pressure is provided with a comparatively high value, in order to avoid the situation where the contact roller is lifted from the winding roll by an unexpected surge in tape tension. it is therefore impossible to adjust the contact pressure and tape tension independently of each other to their optimal values.

It is possible, in principle, to directly measure the tape tension, but this would necessitate an additional measuring device. Even in the case where the latter is provided, the problem of the mutual interaction between the contact pressure and the tape tension would remain.

SUMMARY OF THE INVENTION It is a primary objective of the present invention to overcome the above-mentioned shortcomings by suggesting a winding device in which the measurement and control of the tape tension is obtained independently of the contact pressure.

The invention proposes to attain the objective by suggesting the incorporation of a tape tension measuring means in the contact roller itself. It further suggests the use of the contact roller for the continuous measurement of the winding roll diameter.

A preferred embodiment of the invention suggests that the looping angle within which the tape contacts the contact roller is of such a magnitude that the resultant force of the arriving and leaving tape strands substantially coincides with the plane which is defined by the contact roller axis and the roller support pivot axis. This arrangement provides a measurement of the tape tension independently of the contact pressure. vIt also makes possible the independent adjustment of the tape tension regardless of the contact pressure. A particular advantage of this arrangement resides in the possibility of using a reduced contact pressure, because it is no longer necessary to increase the latter in order to guard against surges in tape tension. This feature is the result of the provision that the resultant force of the tape tension on the contact roller is so oriented that it does not produce a pivoting moment on the contact roller support. For this same reason, the contact pressure is oriented substantially perpendicularly to the resultant force of tape tension on the contact roll.

In order to obtain a continuous adjustment of the tape tension through a change in the drive torque on the winding roll, the invention also proposes a continuous monitoring of the roll diameter. This is accomplished by providing a non-yielding tensile member in connection with the contact roller support, and by driving a displacement measuring device on the winding roll support 'with that tensile member. The result of such an arrangement is a continuous output signal from the displacement measuring device which indicates the instantaneous position of the winding roll support and thus the exact diameter of the winding roll. The latter is a determining factor of the required torque on the winding roll drive for a given tape tension.

The features of this invention may be applied to various types of winding machines. Thus, it is possible to arrange the winding roll support on a carriage which is guided for a straight-line motion, or alternatively on one end of a pivot arm, whereby the winding roll moves along an are. A particularly advantageous arrangement suggests a winding machine witha plurality of winding stations arranged in two parallel rows, oppositely arranged winding stations being alternatingly offset against each other.

BRIEF DESCRIPTION OF THE DRAWINGS Further special features and advantages of the invention will become apparent from the description following below, when taken together with the accompanying drawings which illustrate, by way of example, several DESCRIPTION OF THE PREFERRED EMBODIMENTS The winding device according to FIG. 1 is supported by a frame 1, the latter being part of a machine structure. The particular machine may for instance be a rewinding machine, a slicing machine, a coating machine, a stretching machine, or some other comparable tape processing machine. The tape 2 arrives in the direction of arrow 3 from some other processing station (not shown). It should be understood that the term tape, as used in this disclosure is intended to also cover films and other continuous bands or webs, and particularly thin, stretchable continuous articles.

On the frame 1 is movably arranged a winding roll support 4 which engages frame 1 by means of a carriage guide (not shown). The winding roll support 4 carries the bearings for a roll boom 5. Clamping means between the roll and its boom 5, as well as the boom drive itself, are known and therefore not illustrated in the drawing. The winding roll support 4 is displaceable along frame 1 by means of a lead motor 6 which drives a lead spindle 7 engaging a stationary nut 8 of the winding roll support. The frame 1 further carries an end support 9 on which is mounted a bearing bracket 10 for a vertical pivot beam 11. The latter is attached to end support 9 by means of a pivot 12 so as to represent a first-class lever. The axis of pivot 12 is parallel to the axis of the roll boom Son the winding roll support. The beam 11 is composed of two spaced vertical members 13, of which only one is shown in FIG. 1. Each of the two vertical members 13 has forked ends 14 at its upper end, the forked ends 14 of the two spaced members 13 being aligned in parallel relative to one another and to a vertical plane which includes pivot 12 and the center of the space defined between the forked ends 14. The latter also carry transversely oriented vertically spaced leaf springs 15 which are clamped between separate sections of the forked ends by means of clamping screws 16. The spaced leaf springs 15 in turn carry a bearing block 17 in the center of each vertical member 13 so as to provide a yielding bearing support for the shaft 18 of the contact roller 19. The bearings 17, moving downwardly under an increase .in tape tension, shift a sensing pin 20 toward a displacement measuring device 21 which is attached to the vertical member 13. The displacement measuring device 21 may be in the form of a differential transducer.

On the end support 9 is also arranged a pressure unit 23 whose connecting rod 22 is linked to beam 11. The pressure unit is preferably either a hydraulic or a pneumatic pressure cylinder. When pressurized, the piston rod 22 causes the beam 11 to move around its pivot center 12 in the direction of the double arrow 24. Thus, the pressurization of the cylinder 23 determines the contact pressure between the contact roller 19 and the periphery of winding roll 4.

To the opposite end of beam 11 is connected a nonyielding tensile member 25, preferably a chain, which includes a tensioner 26. The chain 25 is supported by means of guide rollers 27, one of them being mounted on end support 9, the other being mounted on an oppositely arranged stationary support 28. The guide rollers 27 are thus not movable relative to frame 1. On the winding roll support 4 is mounted a sprocket 29 which engages chain 25. The rotation of the sprocket 29 is transmitted via gears 30 and 31 to a rotary transducer 32. The rotary transducer 32 produces an electrical signal which is a measure of the diameter of winding roll 33.

The tape 2, which runs in the direction of arrow 3, passes over the contact roller 19 to be wound onto roll 33. In passing over contact roller 19 the tape contacts the latter over an angle of 180. The forces which are exerted on the contact roller by the arriving strand and the leaving strand of tape 2 thus add up to a resultant force which is twice the tape tension and which is. directed parallel to the two tape strands so as to coincide with the vertical center plane of beam 11, which ineludes the beam pivot 12. The fact that the resultant force of the tape tension thus goes through pivot center 12 eliminates the effect of any changes in tape tension on the pivotal position of beam 11 and on the contact pressure exerted by contact roller 19. On the other hand, a change in the tape tension causes a change in the deflection of the leaf springs 15, as each contact roller bearing 17 is subjected to a vertical force which is equal to the tension. The vertical displacements of the bearing 17 are measured by means of a displacement measuring device 21 and an intermediate sensing pin 20. The displacement measuring device 21 thus gives a direct reading of the tape tension, once the leaf spring deflection has been calibrated.

The contact pressure with which the contact roller 19 is pressed against winding roll 4 is determined solely by the pressure unit 23 and is not influenced by any changes in tape tension.

The device of the invention operates as follows: As the tape 2 is wound onto winding roll 33, the latter increases in diameter, thereby gradually shifting the contact roller 19 to the left, by pivoting the beam 11 in a counter-clockwise direction. The contact pressure between contact roller 19 and winding roll 33, as produced by pressure unit 23, remains constant for all beam positions. The short pivoting motion on beam 11 produces an opposite, approximately lineal motion of the chain 25 which is linked to the opposite end of the beam 11. The chain displacement is transmitted as an oppositely directed displacement to sprocket 29, which in turn repositions a rotary transducer 32 which emits a signal indicating the changed diameter of winding roll 33. After a small pivoting motion of a few millimeters, the beam 11 operates a control switch 35 which faces a contact finger 34 moving with beam 11. The switch 35 operates a control device 37 for the lead motor 6, energizing the latter so as to shift the carriage with the winding roll support 4 in the direction away from the contact roll 19. The latter follows the motion of winding roll 33 as a result of the constant contact pressure imparted to it by pressure unit 23. This follower motion of contact roller 19 is simultaneously registered on the reference chain 25 as an opposite displacement of equal magnitude, due to the fact that the connecting point of chain 25 is at the same distance from pivot 12 as the center of contact roller 19. This chain displacement is transmitted to sprocket 29 by an identical chain displacement in the opposite direction which corresponds exactly to the displacement covered by winding roll support 4. Sprocket 29, therefore, does not rotate as a result of the retracting motion alone, but rotates only in response to an increase in the distancebetween the contact roller 19 and winding roll 33, which is indicative of the winding roll diameter. The reference chain 25 thus acts as a differential drive connection between the contact roller 19 and the rotary transducer 32, registering only the relative displacement between contact roll 19 and winding roll 33, without being affected by their position relative to frame 1. The continued winding operation and the resultant increase in diameter of roll 33 causes the contact roller 19 to pivot again around pivot 12, until the finger 34 actuates switch 35 again, thereby restarting the operation of carriage retraction. The result of this novel drive arrangement is a continuous, accurate measurement of the winding roll diameter which can be used to control the drive torque on roll boom 5 so as to maintain a constant tape tension.

A tape winding machine may comprise several winding units like the one illustrated in FIG. 1. These winding units may be arranged side-by-side with aligned boom axes, or they may be arranged so as to face one another in opposite orientations.

A second embodiment of the invention is illustrated in FIG. 2, where the winding rolls 33 are supported on one end of a pivot arm 41. The representation of FIG. 2 is only schematic, and several elements of the device have been ommited. The tape 2 arriving in the direction of arrow 3 from a processing station (not shown) passes over a guide roller 38 onto separate winding devices 39 and 40 which are arranged side-by-side in two rows and alternatingly offset relative'to similar units in the opposite row. In each unit the tape 2 passes over a contact roller 19 onto the winding roll 33, the latter being carried by a pivot arm 41 which is movable around a pivot axis 42 by means of a pivoting means not shown in the drawing. In this case the winding roll center does not move along a straight line, but follows a shallow arc 43 which is approximately perpendicular to the center plane of the pivot beam 11 which carries contact roller 19.

As in the previously described embodiment, the contact roller 19 is yieldingly supported between the legs of the forked ends of pivot beam 11 which rotates around a fixed pivot center 12. The structure and function of the contact roller 19 and beam 11 are the same as described in reference to FIG. 1. However, in this case the directions of the arriving tape and leaving tape relative to contact roller 19 are not parallel, as indicated by the arrows 44, 45 and 46 which represent the tension forces acting on the tape strands. Force 46 is the resultant force of the two tape tensions 44 and 45. The latter forces are so oriented that the direction of the resultant force 46 is again aimed toward the pivot center 12, thereby eliminating any influence of the tape tension of the contact pressure between contact roller 19 and winding roll 33. The yielding displacement of the bearings for the contact roller 19 is again used as an indication of the tape tension, the deflecting force component on the the leaf springs resulting from the fact that the contact pressure is not exactly perpendicular to the center plane of beam 11 being small enough to be negligible. It was found that in the arrangement of FIG. 2 the tape tension and the contact pressure are sufficiently isolated from each other in their effect on the contact roller bearings that the measurements obtained are adequate for the optimal operation of the device.

An element equivalent to reference chain 25 of FIG. 1 may be included in the embodiment of FIG. 2 for the continuous measurement of the winding roll diameter.

The operation of winding unit 40 is the same as that of winding unit 39, with the only difference that in the latter unit the tape passes under the contact roller 19, while it passes over contact roller 19 in the former unit. The tape tensions acting on the bearings of contact roller 19' are again not parallel, but their resultant force 46 is again aligned with the center plane of beam 11' so that the tape tension is without influence on the contact pressure between contact'roller 19 and winding roll 33. Even though in the arrangement of winding unit 40, the yielding displacement of the leaf springs which carry the bearings of contact roller 19' is in the direction away from pivot centerlZ', their operation is the same as regards the measurement of the tape tenson.

It should be understood, of course, that the foregoing disclosure describes only preferred. embodiments of the invention and that it is intended to cover all changes and modifications of these examples of the invention which fall within the scope of the appended claims.

What is claimed is:

1. An apparatus for winding tape and similar flexible film or web material onto a roll, comprising in combination:

a frame serving as a stationary structural support;

a beam connected to the frame, the beam carrying two spaced, aligned bearings;

a contact roller joumalled in the bearings of the beam;

a winding roll assembly, including a winding roll in parallel alignment with the contact roller, a drive means, and a winding roll support in which the roll is journalled;

means for guidedly moving the contact roller and the winding roll relative to one another along a line which substantially coincides with an alignment plane which is defined by their axes;

means for maintaining a contact pressure between the contact roller and the winding roll at different diameters of the latter;

said beam being connected to the frame by means of a pivot whose axis is spaced from and parallel to the axis of the two contact roller bearings;

said means for maintaining contact pressure engaging the pivotable beam so as to urge the contact roller toward the periphery of the winding roll in a direction which is substantially perpendicular to a beam plane which is defined as including the axis of the aforementioned bearings and the axis of the beam pivot; and

tape tension measuring means including support means on said beam for the contact roller bearings, mounting the same to resiliently yield in the direction toward and from said beam pivot in response to changes in the tape tension, and arranged to yield no more than at most a negligible amount in response to the contact pressure; the yield displacement thus being a measure of only that portion of the contact roller bearing load which is due to the tape tension.

2. An apparatus as defined in claim 1, wherein:

the contact roller and the winding roll are positioned in relation to the direction of tape arrival that the angle defined by the arc of contact between the tape and the contact roller is divided into substantially equal halves by the aforementioned beam plane.

3. An apparatus as defined in claim 2, wherein:

the arc of contact between the tape and the contact roller lies within an angular range of and 200 and is preferably 180.

4. An apparatus as defined in claim 1, wherein:

the beam which carries the bearings for the contact rollers includes a support arm for each bearing, each support arm including means for restricting the yielding motion of the bearing to the beam plane and for biasing the bearing against the effect of the tape tension.

5. An apparatus as defined in claim 4, wherein:

each support arm has a forked end portion with two parallel legs, the contact roller bearings forming part of bearing blocks positioned between the parallel legs; and

the restricting and biasing means are in the form of spaced, parallel leaf springs which hold the bearing blocks between them, the leaf spring being arranged perpendicular to the beam plane so as to yield only in the direction toward and from the beam pivot.

6. An apparatus as defined in claim 5, wherein:

the measuring means includes a displacement measuring device which transduces the deflection of the leaf springs into a control signal for the winding roll drive.

7. An apparatus as defined in claim 1, wherein:

the means for guidedly moving the contact roller and winding roll relative to one another includes a means for retracting the winding roll support away from the contact roller along a straight line within the alignment plane. r

8. An apparatus as defined in claim 1, wherein:

the means for guidedly moving the contact roller and winding roll relative to one another includes a means for retracting the winding roll support away from the contact roller along an are around a distant pivot point, the are being limited by an acute angle and aligned substantially with the alignment plane.

9. An apparatus as defined in claim 7, wherein:

the winding roll support is in the form of a carriage;

and

the retracting means includes: a carriage guide on the frame in parallel alignment with the approach plane; a carriage drive; and means for operating the carriage drive in response to the pivotal position to which the beam is moved by the growing diameter of the winding roll on theone hand, and by the retraction of the carriage on the other hand.

10. An apparatus as defined in claim 9, further comprising:

a means for continuously measuring the winding roll diameter as-a response to the increase in distance between the contact roller axis and the winding roll axis;

the diameter measuring means being responsive to the increase to produce a control signal for the winding roll drive.

11. An apparatus as defined in claim 10, wherein:

the diameter measuring means includes a differential drive connection which responds to the winding roll axis motion and to the contact roller axis motion whereby their displacements in the same sense are substracted from one another, while their dis placements away from each other are added in the signal produced.

12. An apparatus as defined in claim 11, wherein:

the differential drive connection includes: a reference chain extending in a closed, elongated loop parallel to the plane of movement of said .contact roller and winding roll axes and with two stationary guide rollers; a connection between one chain strand and the pivotable beam at a point on the beam which is equally and oppositely spaced from its bearing axis relative to the beam pivot center; and a sprocket joumalled on the carriage and engaging the other chain strand, the rotational position of the sprocket being an indication of the distance between the winding roll axis and the contact roller axis. 

1. An apparatus for winding tape and similar flexible film or web material onto a roll, comprising in combination: a frame serving as a stationary structural support; a beam connected to the frame, the beam carrying two spaced, aligned bearings; a contact roller journalled in the bearings of the beam; a winding roll assembly, including a winding roll in parallel alignment with the contact roller, a drive means, and a winding roll support in which the roll is journalled; means for guidedly moving the contact roller and the winding roll relative to one another along a line which substantially coincides with an alignment plane which is defined by their axes; means for maintaining a contact pressure between the contact roller and the winding roll at different diameters of the latter; said beam being connected to the frame by means of a pivot whose axis is spaced from and parallel to the axis of the two contact roller bearings; said means for maintaining contact pressure engaging the pivotable beam so as to urge the contact roller toward the periphery of the winding roll in a direction which is substantially perpendicular to a beam plane which is defined as including the axis of the aforementioned bearings and the axis of the beam pivot; and tape tension measuring means including support means on said beam for the contact rolleR bearings, mounting the same to resiliently yield in the direction toward and from said beam pivot in response to changes in the tape tension, and arranged to yield no more than at most a negligible amount in response to the contact pressure; the yield displacement thus being a measure of only that portion of the contact roller bearing load which is due to the tape tension.
 2. An apparatus as defined in claim 1, wherein: the contact roller and the winding roll are positioned in relation to the direction of tape arrival that the angle defined by the arc of contact between the tape and the contact roller is divided into substantially equal halves by the aforementioned beam plane.
 3. An apparatus as defined in claim 2, wherein: the arc of contact between the tape and the contact roller lies within an angular range of 160* and 200* and is preferably 180*.
 4. An apparatus as defined in claim 1, wherein: the beam which carries the bearings for the contact rollers includes a support arm for each bearing, each support arm including means for restricting the yielding motion of the bearing to the beam plane and for biasing the bearing against the effect of the tape tension.
 5. An apparatus as defined in claim 4, wherein: each support arm has a forked end portion with two parallel legs, the contact roller bearings forming part of bearing blocks positioned between the parallel legs; and the restricting and biasing means are in the form of spaced, parallel leaf springs which hold the bearing blocks between them, the leaf spring being arranged perpendicular to the beam plane so as to yield only in the direction toward and from the beam pivot.
 6. An apparatus as defined in claim 5, wherein: the measuring means includes a displacement measuring device which transduces the deflection of the leaf springs into a control signal for the winding roll drive.
 7. An apparatus as defined in claim 1, wherein: the means for guidedly moving the contact roller and winding roll relative to one another includes a means for retracting the winding roll support away from the contact roller along a straight line within the alignment plane.
 8. An apparatus as defined in claim 1, wherein: the means for guidedly moving the contact roller and winding roll relative to one another includes a means for retracting the winding roll support away from the contact roller along an arc around a distant pivot point, the arc being limited by an acute angle and aligned substantially with the alignment plane.
 9. An apparatus as defined in claim 7, wherein: the winding roll support is in the form of a carriage; and the retracting means includes: a carriage guide on the frame in parallel alignment with the approach plane; a carriage drive; and means for operating the carriage drive in response to the pivotal position to which the beam is moved by the growing diameter of the winding roll on the one hand, and by the retraction of the carriage on the other hand.
 10. An apparatus as defined in claim 9, further comprising: a means for continuously measuring the winding roll diameter as a response to the increase in distance between the contact roller axis and the winding roll axis; the diameter measuring means being responsive to the increase to produce a control signal for the winding roll drive.
 11. An apparatus as defined in claim 10, wherein: the diameter measuring means includes a differential drive connection which responds to the winding roll axis motion and to the contact roller axis motion whereby their displacements in the same sense are substracted from one another, while their displacements away from each other are added in the signal produced.
 12. An apparatus as defined in claim 11, wherein: the differential drive connection includes: a reference chain extending in a closed, elongated loop parallel to the plane of movement of said contact roller and winding roll axes and with two statIonary guide rollers; a connection between one chain strand and the pivotable beam at a point on the beam which is equally and oppositely spaced from its bearing axis relative to the beam pivot center; and a sprocket journalled on the carriage and engaging the other chain strand, the rotational position of the sprocket being an indication of the distance between the winding roll axis and the contact roller axis. 